Two Freshwater Fish Added To High-Mercury List

Two more types of freshwater fish in southeastern North Carolina have been found to have elevated levels of mercury. They are yellow perch caught south and east of Interstate highway 85, and black crappie caught south and east of I-95. State public health officials are urging pregnant women and children to avoid eating those fish altogether, and urging others to limit their consumption of those fish to no more than one meal a week.

The two species join a growing list of freshwater and saltwater fish that are high in mercury. The state's high-mercury list now includes the following freshwater fish: blackfish (bowfin), wild catfish, jack fish (chain pickerel), warmouth and yellow perch south and east of I-85 and largemouth bass across the state, as well as black crappie south and east of I-95.

Ocean fish on the state's high-mercury list include canned white tuna (albacore tuna), all fresh or frozen tuna, almaco jack, banded rudderfish, cobia, crevalle jack, greater amberjack, South Atlantic grouper (gag, scamp, red and snowy), king mackerel, ladyfish, little tunny, marlin, orange roughy, shark, Spanish mackerel, swordfish and tilefish.

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Pregnant women, women who may become pregnant, and children under age 15 should not eat any high-mercury fish. Other people should eat no more than one meal a week of those fish.

In people, mercury mostly affects nerve cells in the brain and spinal cord, especially in unborn babies and young children. Prenatal mercury exposure can affect the way children think, learn and problem-solve later in life. Adverse health effects can also occur in adults at much higher doses.

Because of the health benefits of fish, however, public health officials urge people to eat a variety of fish that are low in mercury, as fish contain nutrients that help prevent heart disease and that promote healthy nervous systems in children. Women and children under 15 can eat up to two meals a week of low-mercury fish; others can eat up to four meals a week of fish that are low in mercury.

Freshwater fish with lower mercury levels include bluegill sunfish, tilapia, and farm-raised catfish, trout and crayfish. Salmon (canned, fresh or frozen) is also low in mercury. Low-mercury saltwater fish include canned light (not albacore) tuna, black and red drum, cod, croaker, flounder, haddock, halibut, herring, jacksmelt, mahi-mahi, ocean perch, pollock, pompano, sheepshead, sea mullet (southern kingfish), spot, spotted sea trout (speckled trout), tripletail, whitefish and white grunt. Shellfish like shrimp, crab, lobster, clams, oysters and scallops are also lower in mercury, as are farm-raised fish.

Mercury occurs naturally in the environment and is also released into air and water through industrial pollution. When mercury gets into water, it can be absorbed by aquatic organisms, which are then eaten by fish. Mercury can then build up in the muscles and tissues of certain fish. When people eat those fish, they also consume the mercury. The greater the amount of mercury and the longer the exposure, the more serious the human health effects are likely to be. Reducing or limiting dietary intake of mercury is an effective way to reduce potential exposure and adverse health effects.